Abstract: Dual Carbon Goals and resource constraints make it important to understand the evolutionary characteristics and driving mechanisms of the water-energy-food-carbon (WEFC) nexus. We propose a spatially adaptive coupling evaluation (SPACE) model that combines spatial Durbin model (SDM) and the panel threshold model to measure the coupling coordination degree in the WEFC nexus, then analyze the spatial spillover effects and nonlinear influence pathways of 30 provinces in China during 2000—2023. We report the coupling coordination degree in the WEFC nexus to trend upwards, and to fluctuate over this time, with higher levels in the eastern and western regions and lower levels in the central and some inland regions. Science and technology investment reveals a significant positive direct effect and a negative indirect effect, and environmental regulation presents a negative direct and positive spillover effect. Significant threshold effects are apparent for population scale, ecological conditions, and climatic factors, with the direction or intensity of the influence of a variable changing after having crossed a threshold. These findings reveal the spatial differentiation and driving mechanisms of the coordinated evolution of the WEFC nexus, and provide a reference for its regional differentiated governance and high-quality coordinated development.